Alkermes’ new antipsychotic clears FDA advisory committee hurdle

Alkermes’ experimental antipsychotic for schizophrenia and bipolar I disorder ALKS 3831 has cleared an US Food and Drug Administration (FDA) expert advisory committee review.

The joint meeting of the Psychopharmacologic Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee met to discuss ALKS 3831 (olanzapine/samidorphan) for the treatment of adults with schizophrenia and for the treatment of adults with bipolar I disorder.

The committees voted 16-1 that samidorphan meaningfully mitigates olanzapine-associated weight gain and also ruled that the safety profile of the drug has been adequately characterised by 13-3.

ALKS 3831 is a combination of the established oral antipsychotic olanzapine with samidorphan, a mu-opioid receptor antagonist designed to counteract olanzapine-associated weight-gain.

Although olanzapine is an effective and well-established antipsychotic treatment option for patients, its clinical use has been limited by the high-risk of associated weight gain, which results from appetite stimulation.

This increased weight gain can also heighten patient’s risk of cardiovascular disease and reduce their quality of life, leading to poor compliance with treatment.

The committees also jointly voted 11-6 that the labelling is sufficient to mitigate the risks related to the opioid antagonist action of samidorphan.

"The favourable outcome of today's joint advisory committee meeting represents an important milestone for the patients, clinicians and families who may benefit from new medicines for the treatment of schizophrenia and bipolar I disorder,” said Craig Hopkinson, chief medical officer and executive vice president of research & development at Alkermes.

“The personal testimonies shared during today's open public hearing reinforced the need for treatment approaches that consider patients' overall mental and physical health," he added.

Alkermes’ proposed labelling warns against the use of ALKS 3831 in patients who are opioid-dependent or chronically using opioids, and the company has also proposed a comprehensive education plan for the drug which includes dissemination of information to potential prescribers and pharmacists.

The filing of ALKS 3831 is based on two phase 3 studies – ENLIGHTEN-1 and ENLIGHTEN-2 – which respectively demonstrated that the drug was as effective as olanzapine on its own at controlling schizophrenia symptoms and also reduced weight gain.

In the ENLIGHTEN-2 study, patients receiving ALKS 3831 treatment experienced a lower average percent weight gain from enrolment after six months compared with olanzapine, and fewer reached the threshold of a 7% increase at that same time point.

Although the positive committee votes do not ensure approval, they will be considered by the FDA in its review of the new drug application for ALKS 3831, which currently has a target action date for 15 November.